HARRISBURG (WPVI) -- Flu activity around the area is still fairly light, however, the Philadelphia suburbs have the most confirmed cases in all of Pennsylvania.
According to the state Health Department's FluFreePA.com website, there was "regional" flu activity for the week ending Dec. 26.
Bucks County had 33 confirmed cases, Delaware County had 39, Montgomery County had 44 cases, Chester County had 13 and Philadelphia had 24.
Doctors say it often spreads quickly during and after the holidays, when we are usually in contact with more people.
Flu viruses spread mainly from airborne droplets from coughing, sneezing, or talking.
You can also pick it up by touching a contaminated surface, then touching your eyes, nose or mouth.
If you haven't gotten vaccinated yet, experts say do it soon.
"It takes somewhere between two to four weeks for the vaccine to be fully effective, that's why it's important to get vaccinated as early as possible," says Dr. Susan Rehm, an infectious disease specialist with the Cleveland Clinic.
To date, most of this season's flu is Type-A, which tends to make people sicker and cause more complications and hospitalizations.
Type-A was also the dominant strain last season.
Twenty-two people died in Pennsylvania of flu and its complications.
Pregnant women, young children and the elderly are the most vulnerable.
Keep tabs on the season at: FluFreePa.com, and at: CDC's FluView.